extension manager: do not force reload when toggling a brick state

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2844 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
PIMCORE-1941 - Workaround for wkhtmltoimage(-amd64) SEGFAULT (document page preview)

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2845 1f8fe7d8-47f0-464c-8d0a-336f4953ab05